Waterproof fastener stringer and method of producing the same

Abstract

Through-holes are formed at a constant pitch along a side-edge portion of a fastener tape where a tape base fabric is covered by a waterproof layer, the through-holes piercing the fastener tape. Plasma treatment or corona treatment is applied to the side-edge portion of the fastener tape so as to form an activation region on a surface of the waterproof layer on one or both sides of the fastener tape. Injection molding of fastener elements is performed to attach the fastener elements to the side-edge portion of the fastener tape. Melted resin adheres to the activation region and fills the through-hole before solidifying into the fastener element.

The invention claimed is: 
     
       1. A method of producing a waterproof fastener stringer, the method comprising:
 forming through-holes at a constant pitch along a side-edge portion of a fastener tape where a tape base fabric is covered by a waterproof layer, the through-holes piercing the fastener tape; 
 applying a plasma treatment to the side-edge portion of the fastener tape so as to form an activation region on a surface of the waterproof layer on one or both sides of the fastener tape; and 
 performing an injection molding of fastener elements to attach the fastener elements to the side-edge portion of the fastener tape, a melted resin adhering to the activation region and filling the through-hole before solidifying into the fastener element, 
 the method further comprising: applying a plasma treatment to the tape base fabric before the tape base fabric is covered by the waterproof layer. 
 
     
     
       2. The method of producing a waterproof fastener stringer of  claim 1 , wherein the plasma treatment is applied to the side-edge portion of the fastener tape after the through-holes are formed in the side-edge portion of the fastener tape. 
     
     
       3. The method of producing a waterproof fastener stringer of  claim 2 , wherein the plasma treatment is applied to the side-edge portion of the fastener tape so as to remove a thread or fiber of the tape base fabric in the through-hole. 
     
     
       4. The method of producing a waterproof fastener stringer of  claim 1 , wherein said applying a plasma treatment or corona treatment to the side-edge portion of the fastener tape so as to form an activation region on a surface of the waterproof layer on one or both sides of the fastener tape includes:
 forming a plasma-irradiated region on the surface of the waterproof layer in the side-edge portion of the fastener tape; and 
 conveying the fastener tape from an upstream side to a downstream side, wherein 
 the activation region is formed continuously along an elongation direction of the fastener tape. 
 
     
     
       5. The method of producing a waterproof fastener stringer of  claim 4 , wherein a spot diameter of the plasma-irradiated region is greater than a diameter of the through-hole. 
     
     
       6. The method of producing a waterproof fastener stringer of  claim 5 , wherein a spot diameter of the plasma-irradiated region is less than 2 times or 1.5 times of a width of the side-edge portion. 
     
     
       7. The method of producing a waterproof fastener stringer of  claim 4 , wherein a spot diameter of the plasma-irradiated region is less than 2 times or 1.5 times of a width of the side-edge portion. 
     
     
       8. The method of producing a waterproof fastener stringer of  claim 4 , wherein said applying a plasma treatment to the side-edge portion of the fastener tape so as to form an activation region on a surface of the waterproof layer on one or both sides of the fastener tape is performed to skip a portion where a stop member is to be formed in the side-edge portion of the fastener tape. 
     
     
       9. The method of producing a waterproof fastener stringer of  claim 4 , wherein the fastener element includes: a filling portion that fills the through-hole; an upper portion connected to an upper end of the filling portion; and a lower portion connected to a lower end of the filling portion,
 each of the upper and lower portions has a head, a neck and a body, and 
 an end face of the side-edge portion of the fastener tape is positioned in a groove between the head of the upper portion and the head of the lower portion. 
 
     
     
       10. The method of producing a waterproof fastener stringer of  claim 1 , wherein said applying a plasma treatment to the side-edge portion of the fastener tape so as to form an activation region on a surface of the waterproof layer on one or both sides of the fastener tape is performed to skip a portion where a stop member is to be formed in the side-edge portion of the fastener tape. 
     
     
       11. The method of producing a waterproof fastener stringer of  claim 1 , wherein said applying a plasma treatment to the tape base fabric before the tape base fabric is covered by the waterproof layer includes:
 forming a plasma-irradiated region on a surface of the tape base fabric; and 
 conveying the tape base fabric from an upstream side toward a downstream side. 
 
     
     
       12. The method of producing a waterproof fastener stringer of  claim 1 , wherein the waterproof layer is formed onto both upper and lower surfaces of the tape base fabric through the injection molding. 
     
     
       13. The method of producing a waterproof fastener stringer of  claim 1 , wherein the waterproof layer is made of polyurethane, and the fastener element is made of polyamide. 
     
     
       14. The method of producing a waterproof fastener stringer of  claim 1 , wherein the fastener element includes: a filling portion that fills the through-hole; an upper portion connected to an upper end of the filling portion; and a lower portion connected to a lower end of the filling portion,
 each of the upper and lower portions has a head, a neck and a body, and 
 an end face of the side-edge portion of the fastener tape is positioned in a groove between the head of the upper portion and the head of the lower portion. 
 
     
     
       15. The method of producing a waterproof fastener stringer of  claim 14 , further comprising:
 removing one of the upper portion and the lower portion of one fastener element positioned at a middle between both ends of the waterproof fastener stringer; 
 moving a remainder of the upper portion and the lower portion away from an overlap of the both ends of the waterproof fastener stringer and measuring a load required for displacement of the remainder to generate a load curve; and 
 calculating an area of the load curve in an interval in which a measured load value changes from an initial maximum value to zero, wherein 
 S>200 is satisfied where S denotes the area (unit: N*mm) of the load curve in the interval. 
 
     
     
       16. A method of producing a waterproof fastener stringer, the method comprising:
 applying a first plasma treatment to a tape base fabric; 
 covering the tape base fabric with a waterproof layer to configure a fastener tape; 
 forming through-holes at a constant pitch along a side-edge portion of the fastener tape, the through-holes piercing the fastener tape; 
 applying a second plasma treatment to the side-edge portion of the fastener tape so as to form an activation region on a surface of the waterproof layer on one or both sides of the fastener tape; and 
 performing an injection molding of fastener elements to attach the fastener elements to the side-edge portion of the fastener tape, a melted resin adhering to the activation region and filling the through-hole before solidifying into the fastener element.